XML 80 R69.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Consolidated K-Series - Narrative (Details) $ in Millions | Jun. 30, 2018 USD ($) securitization | Dec. 31, 2017 USD ($) securitization | Dec. 31, 2006 securitization | Dec. 31, 2005 securitization
--- | --- | --- | --- | ---
Multi-family collateralized debt obligations, at fair value |  |  |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |  |  |
Carrying Value | $ 9,300.0 | $ 9,400.0 |  |
Weighted average interest rate | 4.05% | 3.92% |  |
Multi-family loans held in securitization trusts |  |  |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |  |  |
Carrying Value | $ 9,300.0 | $ 9,400.0 |  |
Consolidated K-Series |  |  |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |  |  |
K-Series, carrying value | $ 506.5 | $ 468.0 |  |
Consolidated K-Series | K-Series |  |  |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |  |  |
Number of securitizations | securitization | 7 | 7 | 4 | 4

X
- Definition Represents the aggregate carrying value of the investment in the multi-family loans held in securitization trusts. + References No definition available. + Details
Name: | nymt_KSeriesCarryingValue
Namespace Prefix: | nymt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of Securitizations + References No definition available. + Details
Name: | nymt_NumberofSecuritizations
Namespace Prefix: | nymt_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | srt_MortgageLoansOnRealEstateLineItems
Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 948 -SubTopic 310 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-29(Column G)) -URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014 + Details
Name: | us-gaap_MortgageLoansOnRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_MortgageLoansOnRealEstateLoanTypeAxis=nymt_MultiFamilyCollateralizedDebtObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateLoanTypeAxis=nymt_MultiFamilyLoansHeldInSecuritizationTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=nymt_ConsolidatedKSeriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentSecuritiesSeriesAxis=nymt_KSeriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |